intermittent tach and not charging 1994 ocean pro 150

[archcycle]

1994 Ocean Pro 150 - the tach is intermittent, very rarely works but will pop on here and there, and I'm getting about identical 12.4xv while idling and off, then around 10.8-11.2 while under way with the sonar and stereo running. I'm thinking both stator and regulator/rectifier. Not seeing test procedures in my OMC manual. Is there anything I can do here aside from throwing parts at it, or are those two symptoms just certain enough?

I have a spare tach that I tested at the helm end with jumpers off the control wiring and it bumps up when the signal wire first hits it, then back to zero and stays there.

 

[archcycle]

I should add it starts and runs great. I think the tach first started acting up maybe 2+ years ago. But then I only got it on the water 5 times max in 2022 which is Very low for me. Last week I replaced both batteries hoping maybe being 6 years old was to blame for not charging, then yesterday on my way back to the dock, at least a 40 mile round trip, was staring at bad instrument readings and made the connection. Am I correct thinking that as long as I have cranking power to kick it off (i do) then there is nothing dangerous to the rest of the equipment about running this way waiting to confirm the issue and buy the parts?

 

[dingbat]

Last week I replaced both batteries hoping maybe being 6 years old was to blame for not charging, then yesterday on my way back to the dock, at least a 40 mile round trip, was staring at bad instrument readings and made the connection.

Not charging and a cranky tachometer is a sure sign of a bad voltage regulator

 

[archcycle]

Am I off on being worried about the stator too?

 

[saltchuckmatt]

Here is a video of the simple test of a 3 wire rectifier. Remember a rectifier just changes ac energy from the stator to DC current.

This is just testing the diodes but it usually shows the signs of a bad one. There are more complex tests online but watching this simple test gets your feet wet if you haven't done this test before.

 

[saltchuckmatt]

Am I off on being worried about the stator too?

You want to start at the rectifier first because it's easy to get to and easy to test.....then move on.

 

[archcycle]

Assuming I'm going for these burned yellow ACs - both had continuity to ground in both directions and all 4 readings dramatically different. I guess we knew this already but it's still nice to really Know it.

What's next?

 

[saltchuckmatt]

View attachment 373516

Assuming I'm going for these burned yellow ACs - both had continuity to ground in both directions and all 4 readings dramatically different. I guess we knew this already but it's still nice to really Know it.

What's next?

Replace it.

As to why it fried.....I wouldn't know.

I looked up your part and it's pretty pricy so you may want to do more testing of the other components.

I know less about that.

 

[dingbat]

Am I off on being worried about the stator too?

Here is the test procedure to test both the stator and voltage regulator while on the motor.

See any signs of epoxy dripping from stator?
Don’t run the boat until you get this resolved. Will kill stator sooner than later.

https://www.cdielectronics.com/wp-admin/admin-ajax.php?action=cdi_spget&spurl=https://sharepoint.cdielectronics.com/Controlled%20Documents/Installation%20Sheets/IS-193-4093.pdf

 

[Faztbullet]

It is a water cooled rect/reg. A weak impeller will not fill the water passge up internally in the block causing it to overheat and fail. They need a impeller every 2 years no matter how good it pee's

 

[archcycle]

Ok thanks all, got a CDI ordered.
Fazt I confess I haven't replaced the impeller in a while, of course because it has just gone on peeing strong.. I have one around here somewhere though. Something to wrench in the meantime. Every season I've come across i've felt a little guilty

 

[archcycle]

Installed reg/rec. 14.1v at idle and tach is back.

 

[archcycle]

Problem is back. Boat sat most of the winter, maybe put 4 hours on it. High RPMs will occasionally bump the tach on for a moment and spike voltage up to around 12v. What could be killing these things? I did replace the water pump so that's out, I'm not cooking them or at least not this one.

Stator bench test from The Book suggests the stator is grounding. Both Yellow -> Block read 0.1 ohm (s/b very high). Y->Y reads 0.1 ohm then bumps up to 0.2 ohm (s/b <=0.1) which I'm thinking is just my meter being not so great then rounding up.

 

[Faztbullet]

You have a on board charger?

 

[archcycle]

No on board charger, two batteries on a selector, I disconnect when charging.

 

[Faztbullet]

If you flip the selector switch with engine running you risk damaging the rectifier. It needs to be a make before break style or better is a ARC style

 

[archcycle]

If you flip the selector switch with engine running you risk damaging the rectifier. It needs to be a make before break style or better is a ARC style

No problem here, selector is a perko 1/2/all make before break. I only run one battery at a time anyway though.

 

[archcycle]

I went down the Throw Parts route and put another new CDI on it. No change.

I checked the battery connections. All clean and tight and I don't use wing nuts. The cables are only about 2 years old.

At this point I don't see anything else to do but pull the flywheel for a visual. Worst case I just throw ALL the parts at it .... it's already getting hot outside here and I really want to get on the water.

 

[Faztbullet]

I have seen various problem with selector switches. Check connection on the switch and see if you have charging to battery. If battery is charging then your stator is good and rectifier side is working. Check grey wire to tach to see if you have 2-5 VAC at idle, if so then tach is acting up, If not it could be a defective CDI part as their quality is not the best nowdays.

 

[archcycle]

I think I found the problem.